Shape/Shift

“Most people walking along Kingsway aren’t even aware the tower is here…” Nick Durrant of ING Media is describing Space House, the distinctive Richard Seifert and Partners complex that stands at the eastern edge of Covent Garden. His comment hints at the ingenuity shown by architect George Marsh when approaching this tricky piece of urban infill in 1965, and the challenges developer Seaforth Land and its architects Squire & Partners faced over the last year or so when remodelling and upgrading the resulting two buildings. Now in its final stages, I was about to have a sneak preview of the work undertaken so far.

The Seifert name is commonly associated with an architecture of bold geometry, a philosophy carried through every aspect of a building from the essential solid defining its form via the angled piers mediating connection with the street to the dimensional façade that often became its signature. Space House, though less well known than Marsh’s nearby Centre Point, is no exception. Kingsway is fronted with a low, curtain-walled cuboid that falls in with the prevailing massing and elevational treatment of the buildings lining that major thoroughfare. Rising behind and linked to it by a multi-level bridge was that tall, deeply-modelled cylinder that Nick remarked upon, a response to the tapered rear of the plot and the desire for a vertical totem. The resulting pairing read acceptably from any direction.

Of course the very distinctiveness of this style, still striking today, has proven divisive in the past and Nick and I agreed that even ten years ago, arguing to retain such a building would have been an uphill struggle. He also noted that there is still “a lot of anxiety about old office buildings” amongst developers due to the uncertainty and costs associated with conversion. But appreciation of the aesthetic has been improving in recent years, backed by increasing scholarship and popular engagement, whilst the exponentially intensifying sustainability agenda has altered assumptions entirely. As I was to see and hear from Nick and Jon Allgood of Seaforth who had joined us, sensitive restoration of the original architecture and the fullest possible demonstration of environmental concerns are both at the heart of this project.

Mid-century Modernist buildings depend for much of their effect on a reduced palette of self-finished materials. Outside Space House this is evident in the exposed concrete of those subtly articulated piers – impressively scaled, like a giant’s set of jacks – and the skilfully executed planes of mosaic, the tesserae varying in size, colour and orientation, lining portions of the frame, including the undersides of the Kingsway wing. Inside the latter is an elegant freestanding staircase executed in concrete, terrazzo and more mosaic that has now been duplicated in every detail at the opposite end of the block, which will be let separately from the tower though floors can be combined across both. Communal areas are laid with terrazzo tiles.

Two new lift shafts have been added to the four originals and the office floors are of solid, poured concrete. This surprised me given the norm of raised access; the existing 2.7m storey height is the principal explanation, although a drive to reduce materials and their many costs is relevant. A clever solution to the servicing conundrum this throws up has been found at ceiling level, though, where specially-designed chilled beams nestle perfectly within the soffits of the original concrete planks. Wiring, if required (Jon was firm about wi-fi finally being able to fulfil a decades-old promise of cable-free workplaces), will simply pass along surface conduit and be channelled into those floors. An extra, recessed storey has been added to the Kingsway block, housing meeting rooms and a communal Club House.

The tower has gained two further floors itself yet this is almost impossible to detect unless you are told what to look for – I hadn’t noticed myself until reading of the move, even though my office overlooks the site at a high enough level to have had a good view of the project. Retaining the proportional relationship of the shaft to the existing top storey was the main driver for an audacious approach, deemed necessary for Space House’s most recognisable feature.

Like Centre Point before it, Space House’s tower was assembled from bespoke, storey-height, pre-cast concrete cruciform components that had a structural and a decorative function. Forty eight of these, dowelled together with steel pins, made up one ring and thus one floor, repeated up the building; an equal number of T-shaped pieces capped the tower at its summit. Notwithstanding the range of technical questions that such a decision posed, it was determined that for the first of the two new levels this entire process would be recreated from scratch so as to insert a complete new floor to match the original immediately below the T-piece level. This meant removing the latter, fabricating new cruciforms, installing them seamlessly and then refitting the T-pieces. The research, engineering and fabrication effort involved was extensive

though I can vouch for the fact that only a minor difference between old and new concrete is detectable even when on the floor. Eliminating two small lightwells added a modest but useful amount of net internal area to the tower and further lifts were installed here too.

The windows are new throughout and double glazed. A third of them open mechanically as part of a sophisticated mixed-mode natural cooling and heating system that loads and discharges the thermal mass of the concrete frame – left exposed here as elsewhere in the building, a common move today yet one I find unsatisfactory in visual terms – overnight. “It’s about getting used to not having the floor at 21 degrees all year round,” said Jon, “and maybe putting on a jumper!” Referring back to that other goal of respecting the architecture, the spandrel panels in each window unit are now fully glazed and the heating units they hid have been removed but the original external appearance is maintained by clever use of mesh embedded in the glass that is one-way opaque. It was apparent to me that the depth of the cruciforms gives a handy brise soleil effect whilst limiting the view very little, and indeed Jon explained that lights near the perimeter now dim to save energy whilst maintaining lux levels. All of these circular floors are being offered open-plan, though their shape creates what Nick referred to as “gradients of privacy”.

An internal staircase – narrow, gently curving, yet otherwise a miniature of that in the Kingsway block – took us to the new top floor, constructed more conventionally but also considerately recessed and intended also to tidy up the roofscape, returning it to Marsh’s conception of a clean “hat” for the building.

And so to the open-air terrace, another amenity, running around the entire circumference of the roof and offering a truly astonishing view of the capital. I’ve been atop many buildings in London over many decades, of all types, heights and locations, yet I don’t think I have ever been so impressed. A combination of topography, lack of surrounding tall structures and the always-surprising appearance of the twisting Thames when you least expect it gave me a panorama – without even turning, let alone walking – that took in Battersea, Vauxhall, the South Bank, Blackfriars, the Square Mile, Shoreditch and Euston. A trick of atmospherics rendered the view directly ahead as if seen through the compressed perspective of a telephoto lens, with clusters of sharp towers framing a Tower Bridge seemingly at the foot of the hills to the east of the city.

Sadly time flies and we had to return to earth. Crossing one level of the link bridge, its generous width meaning it was “big enough for a floorplate” in its own right, we both observed the original external walkway along one side, and mused as to its intended use. Back on the ground floor Jon pointed out a mosaic-lined staircase ‘discovered’ during the works which Canadian financier and Seaforth founder Tyler Goodwin was keen to preserve. It was a useful introduction to the main reception area, which was just starting to receive its interior finishes. These include ribbed panels made of timber (unlikely, one feels, to be from the tropical hardwoods that were standard in Marsh’s time, but solid enough to my touch) or glass-fibre reinforced concrete, this reusing 90% of the concrete removed during the recent work as a contribution to those sustainability credentials. My guides note that Space House has already achieved a BREEAM ‘Outstanding’ rating at the design stage and the building itself is on target to achieve that in use thanks to the features mentioned and others, plus its all-electric, net carbon zero operational profile. It is also a high-scorer against other testing benchmarks.

We had navigated the current public realm with obvious difficulties given the ongoing activity and hoardings surrounding much of the site although the Kingsway block recently became visible once more. It wasn’t possible, then, to see progress on the eatery being created under the wonderfully expressive cantilevered concrete canopy that once housed a petrol station or whether the mosaic-clad ‘hump’ that contained a ventilation outlet but doubled as a bench remains, though Seaforth and Camden council do have plans to improve the immediate surroundings, including pavement build-outs, food carts and art events. I also didn’t see the basement, where two of the three curving ramps have been removed and where the former car park will contain one of the most comprehensive bicycle and related end-of-journey facilities around.

One can’t come to a firm conclusion about this scheme when much of it is obscured by scaffolding, cable drums and plastic sheeting and the proverbial army of hi-vi’d workers are squeezing their way through half-finished doors and into and out of the only working lift. It remains to be seen whether the architectonic clarity of George Marsh’s design will be preserved, let alone enhanced, when all is complete; whether the final fit out is truly sympathetic to the choices made five decades ago; or whether the building can be properly stitched back into its awkward streetscape (I was reassured by Jon’s answer to my question about the hideous blue railings that previously kept everyone at a distance – they will be removed). Yet the truly heroic effort to extend the tower by revisiting the past is a powerful statement of intent and possibility, the commitment shown to honouring the details is also reassuring and the fact all of this has been done whilst meeting and even exceeding difficult targets for wellness and sustainability proves those two aims I mentioned at the start of this piece are not incompatible. The signs, then, are good, and I’ll certainly be look at the building with new eyes over the next few months as work stops and marketing starts.

At least in the tower there won’t be any arguments over who gets the corner office…

With thanks to Jon, Nick, Tyler, Steve and Amanda Gawthorp